JPS59166483A - Gripper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field of invention 1] The present invention relates to a gripping device for a robot.

[Technical background of the invention and its problems]

Generally, when four bots are used to grasp a workpiece and transfer it to another location, the workpiece may not be in the designated position,
A type of malfunction may cause the robot's gripping device to stop at a position directly above the workpiece. In this case, if the gripping device descends further, it will collide with the workpiece, and there is a high possibility that the gripping device itself and the workpiece will be damaged. However, if the gripping device is damaged, the robot-using system becomes inoperable until the repair is completed, causing serious damage in terms of production control.

[Purpose of the invention]

The present invention was developed in consideration of the above circumstances, and an object of the present invention is to provide a gripping device having a function of preventing damage caused by collision with a workpiece.

[Summary of the invention]

A collision detection mechanism is attached to the fingers of the gripping device that directly grips the workpiece, which detects approach to the workpiece and outputs a collision detection signal to prevent collision with the workpiece.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the gripping device of this embodiment.

The wrist (1) is formed in a cylindrical shape, is connected to an arm (not shown), and is moved up and down in the directions of arrows (2a) and (2b) by a drive mechanism (not shown) such as a DC motor. ing. Further, a hand base (3) is connected to the tip of the wrist (1). A pair of fingers (4a) and (4b) are attached to the hand base (3) so as to be openable and closable.

The mutually opposing surfaces of the lower ends of these fingers (4a) and (4b) are gripping surfaces (6a) that directly grip the workpiece (5)...
), (6b). Furthermore, the base of the hand (3)
is equipped with a motor (7) that opens and closes the fingers (4a) and (4b).
), a feed screw (not shown), and the like. On the other hand, collision detection mechanisms (8a) and (8b) are attached to the lower end surfaces of the fingers (4a) and (4b). FIG. 2 shows the structure of the collision detection mechanism (8a) (the collision detection mechanism (8b) is the same as the collision detection mechanism (8a), so a description thereof will be omitted).

That is, this collision detection mechanism (8a) includes a limit switch 00) embedded in the lower end surface of the finger (4a) with the fixed contact (9) exposed, and an elastic force such as a spring on the lower end surface of the finger (4a). The collision plate α calculated by the body (11),
It consists of a collision plate (movable contact α3 attached to 12) facing the fixed contact (9). Thus,
Collision detector! ffj (sa) and (8b) are separately connected to an electromagnetic relay (15) connected in series to a DC motor CL4) that moves the wrist up and down in the directions of arrows (2a) and (2b) as shown in Figure 3. The collision detection mechanism (8a
), (8b) and at the same time the DC motor (14
) so that the power supply to them is stopped.

Next, the operation of the gripping device having the above configuration will be described. First, in response to a command from the arithmetic and control unit of the robot body, the DC motor a→ is started, and the wrist (1) is lowered in the direction of the arrow (2a). At this time, keep fingers (4a) and (4b) open as much as possible. If the positional force of multiple workpieces (5) arranged at regular intervals on the base 00 is less than that, and there is no malfunction on the robot side, the workpieces (5) will be separated as the wrist (1) is lowered. fingers (4a), (4b
) located between. However, if the workpiece (5) deviates from the predetermined position on the base 00, or if the robot malfunctions due to an incorrect force in the program, when the wrist (1) descends, the fingers (4a) Either or both of (4b) will collide with the workpiece (5) to be gripped or another adjacent workpiece (5). This finger (
4a), (4b) When the tip collides with the workpiece (5), the collision plate (L2) first comes into contact with the workpiece (5), and then
When the wrist (1) descends, the collision plate (one plate) is pushed up in the direction of the arrow (2b) against the elastic force of the elastic body circle.

Then, the movable contact 03) contacts the fixed contact (9), the limit switch of the collision detection mechanism (8a) is closed, and a collision detection signal is applied to the electromagnetic relay cL. In this electromagnetic relay (151), when the above-mentioned collision detection signal is input, the circuit is opened and the DC motor 0 that drives the wrist (1) up and down is activated.
4) is stopped, the DC motor α (a) stops rotating, and the gripping device is rotated by the fingers (4a) and (4b).
) stops its downward movement just before it collides with the workpiece (5). Therefore, the gripping device will not be damaged due to collision with the workpiece (5). In other words, the gripping device of this embodiment can handle a plurality of closely arranged workpieces (5).
It is particularly effective when taking out a specific workpiece (5) from...

In addition, in the above embodiment, the collision detection mechanism (8a),
The collision detection signal output from (8b) is applied to the electromagnetic relay 09, but the collision detection signal is applied to the arithmetic control section of the robot body, and the gripping device is activated based on the command from this arithmetic control section. The exercise may be stopped. In addition, if there is a risk that the gripping device may collide with the workpiece due to rotational movement, horizontal movement, etc. and be damaged, as shown in Fig. 4, Surface (6a).

(6b) is excluded. ) may be attached with a collision detection mechanism surface. Further, in the above embodiments, the collision detection mechanisms (8a) and (8b) utilize IJ Mitswitches for collision detection, but the collision detection mechanisms (8a) and (8b) utilize magnetic field energy to non-contactly detect the approach of the workpiece. Switch (Proxy
ml ty Switch) or an ultrasonic switch using ultrasonic waves may be employed. Furthermore, in the above embodiment, the opening/closing mechanism of the fingers (6a) and (6b) includes:
Although a feed screw and a motor are used, a gripping device that uses a gear mechanism as a power transmission mechanism, a link mechanism as an actuator, and hydraulic pressure or air pressure may also be used.

〔Effect of the invention〕

The gripping device of the present invention has a danger prevention function that detects the approach of the fingers to the workpiece and outputs a collision detection signal.
To apply force without damaging the gripping device or the workpiece. Therefore, it is possible to prevent a situation in which the gripping device is damaged and the pot becomes unusable, and the system using the robot becomes inoperable even after the repair is completed, resulting in a significant drop in production efficiency.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a gripping device according to an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part of Fig. 1, Fig. 3 is a diagram showing the electrical connection relationship of the collision detection mechanism, and Fig. 4 FIG. 3 is a side view showing another embodiment of the present invention. (3) Second hand leather part, (4a), (4b): fingers, (5): workpiece, (7): motor (opening/closing mechanism), (8a), (sb), αη: collision detection mechanism. Agent Patent attorney Kensuke Chika (and 1 other person) (7) Army 16 Army 3 figure 6 Senior 2 figure Y4 figure

Claims (2)

[Claims] (1) at least a pair of fingers that grip a workpiece; a hand base that supports these fingers so that they can be opened and closed; an opening/closing mechanism that is attached to the fingers and that opens and closes the fingers; A gripping device comprising: a collision detection mechanism that detects the approach of fingers to the workpiece. (2) The gripping device according to claim 1, wherein the collision detection mechanism is attached to the tip end surface of the finger.